Resistance.



J. L. DINSMOOR.

RESISTANCE.

APPLICATION 1311.111) JAN. 29, 1905.

Patented Jan. 26, 1909.

IN VEN TUH 7B727zZ. Dinsmoo7" WITNESSES A TTORNEYS JOHN L. DINSMOOR, OF NEW YORK,

N. Y., ASSIGNOR TO HERMANN M. HIRSOHBERG, OF NEW YORK, N. Y.

RE SISTANCE Specification oi Letters Patent.

Patented Jan. 26, 1909.

Application filed January 29, 1908. Serial No. 413,178.

To all whom it may concern:

Be it known that 1, JOHN L. DINsiroon, a citizen of the United States, residing in the city of New York, borough of Brooklyn, county of Kings, and State of New York, have invented a certain new and useful Resistance, of which the following is a specification.

This invention is a resistance adapted for use in connection with electrical apparatus.

Various types of electrical resistance are known in the art, such devices for are lamps being usually embodi d in, and forming a part of, the lamp structure. So far as I am aware, however, there exists a demand in the trade for an individual resistance, t. 6. one separate from the electrical structure and adapted for use, more particularly, in conjunction with said structure, such as an arc lamp.

The object of this invention is to meet the practical requirements of an individual or separate resistance, although it should be understood that certain features of the invention are susceptible of embodiment in resistances which form integral parts of elec trical apparatus.

There are numerous practical requirements to be fulfilled in a resistance such as contemplated by this invention, chief among which are the ability to rapidly dissipate the heat which is necessarily evolved in the passage of an electric current through the resistance material, compactness in construction, economy of manufacture, durability and efficiency in use, and the exclusion of rain and snow from the working parts of the resistance when the latter is used in a position exposed to the weather.

In carrying the invention into practice, the new resistance is constructed to secure thorough ventilation by the circulation of air, through all parts of the structure, whereby the heat evolved by the passage of an electric current is thoroughly dissipated, with the result that the structure does not become overheated, cracking, breaking and deteriorating of the parts are precluded, and the resistance can be used indoors to as good advantage as in the outdoor air.

With a view to securing compactness in construction, as well as relatively large surface for the radiation of the heat, the resistance material is split up or divided so as to produce a number of metallic coils, each of which is wound on a ventilated spool composed of a large mass of insulating material, such as porcelain. It is preferred in one form of the resistance to employ spools which are substantially oval in cross section, for the reasons that a relatively large number of said spools can be grouped within a given space, and the surface of each spool presents a large area for the resistance wire.

An important feature of the invention is a perforated base, and apertured spools attached to said base in a way for air to circulate freely through the base and the spools, as well as around the spools. It is preferred to arrange the spools in mechanical engagement with the base, and to fasten the spools to the base by devices which do not obstruct the air passages through the spools or the base. Furthermore, it is preferred to employ a top or cover which is free from engagement with the spools, said cover being, moreover, spaced with relation to the casing in order that the heated air may escape freely through the space intervening the cover and the casing.

Other features of the invention will be hereinafter more fully pointed out in the following description taken in connection with the drawings.

In the accompanying drawings, I have illustrated one practical embodiment of the invention, but the construction shown therein is to be understood as illustrative, only, and not as defining the limits of the invention.

Fi ure 1 is a plan view, partly in section, of a resistance embodying my invention, the plane of the section being indicated by the irregular line 11 of Fig. 2. Fig. 2 is a ver tical section, partly in elevation, the plane of the section being indicated by the irregular line 2-2 of Fig. l.

A designates a base or base member which consists, preferably, of a comparatively thin metallic plate or disk. The working parts of the resistance are housed within a suitable casing, B, over which is arranged a cover, C. As shown, the casing, B, is provided with a flange, 5, the latter embracing the edge of the base member, A, so as to fit snugly thereto by a substantially weather proof joint. The cover, C, is cast in one piece with a depending curved flange, c, the diameter of which exceeds that of the casing, B, and said cover is provided, furthermore,

with internal lugs, c. Said lugs are integral with the cover and they are provided with notches, 0 whereby the lugs are adapted to fit on the top edge of the casing, B, in a manner to space the flange, 0, of the cover rela tive to the casing, B, thus roducing a ventilating space, Z), between t e cover and the casing, see Fig. 2. The described construction of the parts, A, B, 0, enables them to be easily, quickly and rapidly assembled, and the lugs, 0, determine the relationship of the cover, 0, to the casing, B, thus forming the ventilating opening. As shown in Fig. 2, the edge, 0, of the cover extends below the top edge of the casing, B, thus precluding the admission of rain and snow to the interior of the a paratus, but at the same time the edges of t e cover and the casing are so s aced as to allow the air to circulate freely t rough the opening or s ace, 6.

The several parts, A, C, are clamped or held together by any suitable means, but as shown in the drawings, I employ a bolt, D, which passes centrally through the base, A, and the cover, 0. As shown, the bolt is pro vided at its lower part with an eye, d, and around the bolt is loosely fitted a sleeve, e, the respective ends of which engage with the base member, A, and the cover, C. The upper threaded end of the bolt, D, passes through the bottom portion of a yoke shaped hanger, F, and on said threaded end of the bolt is screwed a clamping nut, d. Said nut serves to draw the eye, d, of the bolt into engagement with the base member, A, and thereby clamp the sleeve, e, into close engagement with the cover, C, and the base member, A, while at the same time the hanger, F, is attached to the bolt and the cover. The structure is thus provided with a single bolt which serves the two-fold purpose of clamping the parts, A, B, C, together and of suspending the entire resistance. As shown in Fig. 2, the hanger, F, is provided with a pin or key, f, on which is loosely mounted a sheave,f, composed of insulating material, such as porcelain, whereby the hanger is adapted to serve as a means for suspending the resistance from a hook or other fixture. Connected loosely with the eye, d, at the lower end of the bolt, D, is a hook, F, adapted to be engaged with an arc lamp or other electrical apparatus, thus making provision for sus ending said lamp from the resistance, and ringing the resistance and the lamp into compact relation to each other. The base member, A, is shown as having ventilating openings, at, a, and other openings, (1?, the latter being outside of the circle of ventilating openings.

The electrical resistance material consists preferably, of metallic wire or ribbon, and for the purpose of compactness in construction, as well as to make provision for a considerable quantity of material to offer the required resistance to the passage of a current, I prefer to divide the resistance into a plurality of units, each consisting of a spool and a coil. In the example of the invention shown in the drawings, the resistance coils are divided or grouped into two series, and the coils are connected in parallel series.

G, G, G designate one series of spools, and H, H, H are the spools of the other series, each of said spools containing the resistance coil, 1. Each spool consists of a mass of insulating material, preferably porcelain, and said spool is substantially oval shaped in cross section, although it is not desired to limit the invention to the described material and this particular shape. Fur thermore, each spool is provided with a ventilating opening, g, and with other smaller openings, h, the openings, h, being independent of the ventilating opening and situated, preferably, on opposite sides thereof. Furthermore, each spool is provided in its respective ends with a recess or slot, 01, the latter being radial to (although not communicating with) the ventilating opening, 9. The inner portion of the recess or slot, i, is enlarged, as indicated at i.

The s ools of insulating material are imposed directly on, and engage mechanically with, the base member, A, and each spool is fastened securely to said base member by means which do not obstruct the ventilating opening, g. Each spool is so positioned on the base member that its ventilating opening, g, is in alinement or register with one of the ventilating openings, a, of said base member, whereby the air is free to pass through the alined openings, a, g, and into the space or chamber formed below the cover, C. Each spool may be fastened to the base member by any appropriate means, but for simplicity of construction, it is preferred to employ the cotter pins, J. Each spool is held in place by two cotter pins which pass upwardly through the base member, A, and through the openings, h, of the spool, the upper ends of said pins being bent as at into engagement with the top of the spool. The cotter pins hold the spool firmly in engagement with the base member, and each spool is confined in place so as to permit it to expand or contract under changes in tem erature, thus overcoming one of the particu ar objections to rheostats, namely, the liability of the porcelain spool to crack or break owing to temperature changes.

An advantage of the oval construction of the spools is that they may be grouped in compact order within a given radius, as shown in Fig. 1, and a further advantage is that the external radiating surface of each spool may be quite large, whereby the required amount of resistance wire may be coiled on the spools comprising the group employed in the resistance. As shown, the

external surface of the oval shaped spool is provided with grooves in which the convolutions of the resistance coil, 1, are laid, and the res ective ends of each coil are connected to the binding screws, K, K. Each screw is placed in one of the recesses, 41, two or which are provided, one in each end of the spool. The threaded end of each screw works in a nut, 7r, which occupies the enlarged end of tue recess or slot, 2', so as to be held from turning therein. Next to the headed end of the screw is a metallic washer, Z, which cooperates with the washer, Z, composed of insulating material, such as mica, and between the washers, Z, Z, is clamped an end portion of the resistance coil. Between the resistance coils are the connecting members, L, which may be formed by extending a portion of one coil from one spool to the next spool, so that the connecting member may be clamped in electrical engagement with the next coil by one of the screws K.

M, M, designate the binding posts which may be of any usual or preferred construction, and as shown in the drawings, these posts are at opposite sides of the resistance. Said posts extend through two of the openings, 61, of the base member, and by using a number of these openings the posts, or either of them, may be placed at different positions on said base member, whereby the posts may be positioned according to the number of spools and coils which may be used in the resistance. As shown, the post, M, isprovided with two twisted wires, m, one of which connects with the coil of the spool, G and the other wire with the coil of the spool, H The coil of the spool, G is connected in series with the coil of the spool, G, and the coil of the spool, G, is connected in like manner with the coil of the spool, G. This connection of the coils in series is retained for the spools, H, to H, and thence to H, and finally the coils of the spools, G, H, are connected with the binding post, lvl, whereby two series of coils are connected in parallel series between the binding posts, M, M.

By reference to Fi 2, it will be noted that the spools do not extend to the top edge of the casing, B, and hence the cover 0, is not connected mechanically with the spools, thus making the cover independent of the spools. When the resistance is in use, the current passes through the coils of the two series of spools, and the resistance offered by the coils induces a certain amount of heat. The heat is absorbed partly by the material of the spools, and is radiated from the surface of the spools. As each spool consists of a mass of material, its heat conducting properties are augmented, but by providing each spool with an axial opening, 9, the aggregate radiating surface of the spool is materially increased, so that the spool will be cooled both internally and externally by the circulation of air through and around the same. When the spools are heated by the resistance coils, the heat is conducted par to the base member, A, and in service the heat raises the temperature of the base member, A, to a point somewhat above the temperature of the cover, C, notwithstanding that the cover is exposed to the ascending currents of heat which circulate through the resistance. I attribute this condition to the fact that the spools are heated b the coils and that said spools are imposed on the base member so as to have mechanical engagement therewith. When the spools are heat ed, an upward circulation of air is induced through the openings, at, g, of the base memher and the spools, and at the same time, the air is free to circulate through the openings, a, a of the base member. The ascending currents of heated air strike the underside of the cover, C, the latter being curved or lashioned to defiect the air toward the opening, I), and thus provision is made for the circulation of air, not only through the casing, but through the resistance units, 2'. c. the ventilating opening, of the spools.

From the foregoing description, it will be noted that each resistance coil has a venilated core, the cores being so arranged that a draft of air is produced thercthrough when the resistance is in use. The small opening, ft, in each spool retains an internal mass of material which is exceptionally heavy and which tends to increase the effective heat conduction of the spools, the oval form of the spool in cross section increasing the heat radiation and affording a greater surface for winding the resistance material than a cylindrical spool affords.

The form of the spools and their arrangement within the case and on the base member produces a compact construction, and enables me to reduce the size of the resistance. The resistance possesses many other advantages from a practical standpoint, and it is especially marked for its economy of manufacture.

Having thus fully described the invention, what I claim as new, and desire to secure by Letters Patent is:

1. In an electrical resistance, a casing, base member provided with openings, a plurality of hollow resistance units within a single chamber of said casing and in communication with the openings of said base member, whereby air may circulate upwardly through the resistance units and the chamber of the casing, a substantially imperiorate cover engaging with the upper part of the casing, said cover being spaced relative to the upper edge of the casing and providing an opening for the free exit of heated air from the upper part of said casin means I u 0 o for suspending the electrical reslstance, and

means for retaining the cover in fixed relation to the casing.

2. In an electrical resistance, a casing, a base member provided with openings, a top member, a plurality of hollow spools each of which is in communication with an opening in the base member, the upper part of said spools being disconnected from said top member, and means separate from the top member for securing the spools individually upon said base member.

3. In an electrical resistance, a casing provided with a perforated base member, a plurality of spools fixed to said base member, said spools being disposed in substantially overlapping relation to each other and free from contact, and coils on said spools.

l. In an electrical resistance, a casing having means for the circulation of air therethrough, and a plurality of ventilated resistance elements within said casing, each resistance element being substantially oval shaped in cross section, said elements being assembled in substantially overlapping order and free from contact with each other.

5. In an electrical resistance, a casing provided with a base member and a removable cover, suspending means cooperating with said casing, said suspending means operating to clamp said coverfixedly in position on the casing, and resistance units supported within the casing and disconnected from the removable cover thereof.

6. In an electrical resistance, a spool composed of a mass of insulating material which is substantially oval in cross section, said spool having a ventilating opening, whereby a large radiating area is produced on the surface of the spool for the reception of appropriate resistance material.

7. In an electrical resistance, a plurality of spools each composed of a mass of insulating material which is substantially oval in cross section, each spool having an unobstructed ventilating opening, whereby the oval spools may be grouped compactly within a given radius, and each spool provided with a relatively large radiating surface for the reception of appropriate resistance material.

8. In an electrical resistance, a perforated base member, a group of insulating spools,

disposed in substantially overlapping order on the base, but free from contact with each other, each spool having an opening in register with an opening in said base member, and resistance material wound on said spools.

9. In an electrical resistance, perforated base member, a group of insulating spools each substantially oval shaped in cross section and grouped in compact order on the base member, said spools being in substan tially overlapping relation, but free from engagement with each other, and each spool having a ventilating opening in register with an opening of the base member, and resistance material coiled on said spools.

10. In an electrical resistance, a casing, a base member, a removable cover for said casing, a suspending member passing through said cover and the base member, means cooperating with the cover and said suspending member for retaining said cover in position relative to the casing, and resistance units positioned within a single chamber of said casing.

11. In an electrical resistance, a casing provic ed with a perforated base member, a substantially imperforate cover having means whereby its edge is spaced relative to the upper edge of said casing, thereby producing an opening for the free exit of heated air from the upper part of said casing, means for suspending the electrical resistance, resistance units positioned within a single chamber of the casing, and meanscobperating with said suspending means and the cover for retaining the latter in position.

12. In an electrical resistance, a erforated base member, perforated spoos attached to said base member, each spool having an opening which is in register with an opening of the basamember, a casing, and a cover provided with lugs which engage with the casing and operate to space the cover and the casing so as to provide a space for the circulation of air.

13. In an electrical resistance, a casing provided with a perforated base member, an imperforate cover separable from said casing, means for suspending the electrical resistance and operating to clamp the cover to the casing, and resistance units fixed to the base member and positioned within the casing, said resistance units being disconnected from the cover.

14. In an electrical resistance, a base member having ventilating openings, a plurality of resistance units open for the circulation of air therethrough, a casing, a cover having spacing means engaging with said casing, and means for clamping the casing between said base member and the cover.

15. In an electrical resistance, a resistance spool provided with an unobstructed ventilating opening, and with other openings adapted to receive suitable fastening devices.

16. In an electrical resistance, composed of a mass of insulating material, said spool being rovided with a ventilating opening, and wit a slot or recess extending substantially radially with respect to said ventilating opening.

17. In an electrical resistance, a spool composed of a mass of insulating material, said spool being provided with a ventilating opening, and with a slot or recess extending i substantially radially with respect to said a spool.

ventilating opening, the inner end portion of said slot or recess being ofgreater width than the remainder thereof.

18. In an electrical resistance, a base member having ventilating openings, a plurality of spools each having a ventilating 0 ening in register with one of said openings oi the base member, and means for fastening the s 001 in position on the base member, said fastening means leaving the ventilating openings free and unobstructed.

19. In an electrical resistance, a base member having ventilating openings, a plurality of spools each having a ventilating opening in register with one of said openings of the base member, and fastening means attached to the base and to each spool in a manner to leave the ventilating openings free and unobstructed.

20. In an electrical resistance, a base member having ventilating openings, a plurality of spools each having a ventilating opening in register with one of said openings of the base member, and pins attached to the base and extending through said spools for fastening them directly to the base, said pins leaving the ventilating openings unobstructed for the free circulation of air therethrough.

21. In an electrical resistance, a plurality of spools each composed of a mass of resistance material, each spool having a transverse slot or recess, a coil on each spool, a connecting member between the coils, and a screw countersunk in the recess or slot and clamping the connecting member to the spool.

22. In a device of the class described, a spool composed of insulating material and substantially oval in cross section, said spool being provided with a ventilating opening and provided, also, with other openings which are adapted to receive devices whereby the spool may be secured in position.

23. In a device of the class described, a 1

s 001 com osed of insulating material and provided with a ventilating opening, a supporting plate on which the spool rests, and fastening means engaging with the spool for holding it fixedly in position on said plate, said fastening means being positioned to leave the ventilating opening free or unobstructed.

24. In a device of the class described, a spool composed of insulating material, said spool being provided with a substantially central ventilating opening, and provided, also, with other openings, a supporting plate for said spool, and means positioned in said last mentioned openings for securing said spool fixedly in position on the plate.

25. In a device of the class described, a spool composed of insulating material, said spool having openings, an electrical resist ance wound on said spool, a supporting plate, and fastening means positioned in said openings for securing the spool fixedly in position on said supporting plate.

26. In a device of the class described, a spool composed of insulating material and provided with a substantially central ventilating opening, a supporting plate, an electrical resistance wound on said spool, and fastening means engaging directly with said spool for securing it fixedly in position on said supporting plate, said spool fastening means being positioned externally with respect to said ventilating opening whereby said opening is left unobstructed for the free circulation of air therethrough.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

JOHN L. DINSMOOR.

Witnesses:

M. SooFIELn, H. M. HINDTNA. 

